Those waves that people think that coral don't need or use sure do some cool stuff, huh? In all seriousness, I had to move to 10K as a compromise since the wattage to balance out a 6.5K was so intense, but this was all halide and maybe a 6.5k T5 or two are in my future since they won't take as much to overpower. IMO, I would run the 6.5K during the whole time that you don't need to view the tank and scale them back when you just want to illuminate - let them go to work when you won't see the more-yellow tint and turn them off when you get home.

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I work from home and walk past my tank several times a day. I don't mind a yellowish look most the day to be honest. Some corals actually look BETTER under it (tierra del fuego) in my opinion, while other look pretty blah (JF solar flare, similar to RMF acid trip mille).

6500k is the color of a slightly overcast day. People have been growing corals under 6500k halides for many years. Of course it will grow corals. It's a nice white light source that looks good to our eyes. No, you don't get that florescent glow that you get under intensely blue lights... but you don't get that in the ocean either!

I think that if you had any kind of breath and depth of personal experience with these other lighting sources, you would not think that your point is all that relevant. While it is fun to talk about academically and wonder about, there is no practical experienced-based argument to be made - a 6.5K light will outperform nearly anything else on the market for growth and rendering color... they just do not illuminate the color very well at all and the tradeoff of having so much more wattage dedicated to blue is not worth it to many people. If you take a frag out of a tank lit only by 6.5k light and then immediately put it under a 20K light source, they look amazing.

You probably don't know much about where coral is collected if you think that a sizeable chunk is at 30 meters - the rebreathers and equipment necessary makes this terribly expensive and dangerous and nobody could afford the coral. The guys that we saw have a mask, bag and saw and they hold their breath.

I think that it is OK to admit that we don't know as much about spectrum as we thought. A few LED iterations ago, UV was worthless and you were a fool for mentioning that it was handy. Now IR is making a comeback. Some panels are upping the red, yellow and green. With every new iteration, more and more elements of natural sunlight are being re-added. I know that it is easy to believe a LED manufacturer, supplier or the like with the argument that they can do better than millions of years of evolution and adaptation, but that probably is not the case as much as it is. What we are doing is tailoring the light to our needs since people like the colors under more blue conditions.

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I stopped reading this after you got nasty in the first sentence. Ain't nobody got time for that.

The blue peaks in a lot of the windex looking tanks is wasted light............corals don't need all that.
The blue peaks are for our eyes to see the colors.

You want great growth and color , especially on acros you need full spectrum lighting from 400-600 to satisfy all the different pigments.......we don't know which pigments are in each species of corals.

The balance is trying to get what the corals need and what we want to see with our eyes.

That's why over driven Radiums are so popular.......they can produce the look we want and still satisfy the amount of the other spectral colors the corals need.

Since LEDs have been around you can set up all kinds of wacked out Spectral distributions that the corals aren't going to thrive under. This was especially a problem early on due to design(ratio of the diodes) and also in how they were setup and programmed to run.

Over the past year or two it's been easier as violets were added in higher amounts and the number of white to blue ratio was widened. Add to that control over each color and it's become easier to mimic a Radium bulb.

The blue peaks in a lot of the windex looking tanks is wasted light............corals don't need all that.
The blue peaks are for our eyes to see the colors.

You want great growth and color , especially on acros you need full spectrum lighting from 400-600 to satisfy all the different pigments.......we don't know which pigments are in each species of corals.

The balance is trying to get what the corals need and what we want to see with our eyes.

That's why over driven Radiums are so popular.......they can produce the look we want and still satisfy the amount of the other spectral colors the corals need.

Since LEDs have been around you can set up all kinds of wacked out Spectral distributions that the corals aren't going to thrive under. This was especially a problem early on due to design(ratio of the diodes) and also in how they were setup and programmed to run.

Over the past year or two it's been easier as violets were added in higher amounts and the number of white to blue ratio was widened. Add to that control over each color and it's become easier to mimic a Radium bulb.

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Hey BigE, wouldnt you agree that a 50/50 blend of blue plus and coral plus bulbs has a better spectral composition for corals then say all 6500k tropics? They provide all of the needs in the corals and dont waste light on spectrums they dont. Sure the 6500k would work, but the coral plus and blue plus combo provide more punch in the correct spectrums since less is wasted on others. That is what I am trying to say here. There are better light sources for corals than a 6500k bulb.

On the LEDS, another reason why people are more successful now is because of things like "kessil logic" and radion pre-sets like SBS AB+, as well as the information provided by BRS and Ecotech CoralLab, plus this forum!

An interesting debate that reminds me of the old MH arguments and people tearing each other apart over 10k bulbs being too blue and actinic will kill all your corals.

These days we have so many options and there are documented success growing coral under just about everything. Pick a spectrum you like visually and be happy. We can easily add power if you want more PAR or PUR and there are so many things that impact growth more than spectrum (ok, I am talking about normal reefing bulbs - not something silly like 100% green LEDs) heck I have used 6.5k MH, 15kMH, all sorts of T5, PC, blue/white led, blue only LED, full spectrum LED, t5/LED combo - they all grew coral like weeds. If you are having trouble with coral growth it's not the spectrum, add or relocate a pump for flow, increase or decrease intensity, look at the tank chemistry more closely or best yet, spot feed appropriate sized food.

The spectrum seems to play such a minor role in coral growth (again, with normally used reef lights) compared to those other factors I listed that if you like 6.5k then run it! Like heavy blue? Run it! I think the valid point is that the more actinic the more fluorescence but you can wash out other colors with too much blues but whatever someone enjoys.

I do like the point that replicating nature isn't always the most ideal solution, there are so many variables in the ocean that we simply can't replicate in our living rooms and the example of tide pool coral growing slowly due to photoinhibition is a good one. Unless you like the look in which case there is 0 issues! We get caught up in "the best" argument a lot and it typically brings two things to mind.

1) there isn't anywhere nearly enough data out there to make that conclusion for each species and even individual morphs of a species
2) many times what people are arguing about isn't enough to make a significant impact anyway, it's just getting caught up in semantics

Hey BigE, wouldnt you agree that a 50/50 blend of blue plus and coral plus bulbs has a better spectral composition for corals then say all 6500k tropics? They provide all of the needs in the corals and dont waste light on spectrums they dont. Sure the 6500k would work, but the coral plus and blue plus combo provide more punch in the correct spectrums since less is wasted on others. That is what I am trying to say here. There are better light sources for corals than a 6500k bulb.

On the LEDS, another reason why people are more successful now is because of things like "kessil logic" and radion pre-sets like SBS AB+, as well as the information provided by BRS and Ecotech CoralLab, plus this forum!

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Coral+ and Blue+ is a nice balance for ambience (our eyes) and coral needs, but it wouldn't compete with the growth a 65k Iwasaki can produce.

This gets back to what jda was trying to explain to you.......... You're just misinterpreting, have it backwards slightly. There is more spectral waste today under setups than there ever was before under MH bulbs in general. It's part of what I was trying to explain to you in my thread. Excessive peaks regardless of which color can be detrimental because it creates a wacked out spectral distribution across the tank. Some corals may get what they want and some don't get what they need to thrive and color. You can do this with rainbow combos in T5s but you aren't generally going to trash corals.

As far as Echotech and BRS.............they're just trying to re-invent the wheel. The recommendations, how to set up.design ect. LEDs have been out there for 5+ years. People just weren't listening. It's always been more about spectrum than par.

An interesting debate that reminds me of the old MH arguments and people tearing each other apart over 10k bulbs being too blue and actinic will kill all your corals.

These days we have so many options and there are documented success growing coral under just about everything. Pick a spectrum you like visually and be happy. We can easily add power if you want more PAR or PUR and there are so many things that impact growth more than spectrum (ok, I am talking about normal reefing bulbs - not something silly like 100% green LEDs) heck I have used 6.5k MH, 15kMH, all sorts of T5, PC, blue/white led, blue only LED, full spectrum LED, t5/LED combo - they all grew coral like weeds. If you are having trouble with coral growth it's not the spectrum, add or relocate a pump for flow, increase or decrease intensity, look at the tank chemistry more closely or best yet, spot feed appropriate sized food.

The spectrum seems to play such a minor role in coral growth (again, with normally used reef lights) compared to those other factors I listed that if you like 6.5k then run it! Like heavy blue? Run it! I think the valid point is that the more actinic the more fluorescence but you can wash out other colors with too much blues but whatever someone enjoys.

I do like the point that replicating nature isn't always the most ideal solution, there are so many variables in the ocean that we simply can't replicate in our living rooms and the example of tide pool coral growing slowly due to photoinhibition is a good one. Unless you like the look in which case there is 0 issues! We get caught up in "the best" argument a lot and it typically brings two things to mind.

1) there isn't anywhere nearly enough data out there to make that conclusion for each species and even individual morphs of a species
2) many times what people are arguing about isn't enough to make a significant impact anyway, it's just getting caught up in semantics

Back in the dark ages (pun intended) we were pretty limited in lighting choices as far as metal halides went. The commercial coral farm I managed for a couple of years used only 6500K Iwasaki lamps and had great success. Many old timers to this day in the hobby still claim these lamps produced superior coral growth. I have some theories as to why and they are:
1. PAR meters don't measure the UV-A 365nm mercury spikes in these (or any) lamps. This energy is useful in photosynthesis. If we look at the pigments that protect against UV (the mycosporine-like amino acids, or MAAs) there are none that absorb UV energy at 365nm. There's a good reason for that.
2. The green light, what there is of it, borders on the absorption bandwidth of the accessory pigment peridinin. It's impact is positive, but probably minimal when compared to other bandwidths, but positive none the less.
3. The infrared energy relaxes pressure on Photosystem II by stimulating Photosystem I.
4. As far as coloration goes, we grew the Purple Monster Acropora successfully and it had magnificent color. Many of the other stony corals were quite colorful as well. Although not discussed much greenish-yellow/yellow light seems to induce non-fluorescent red coloration in those stony corals capable of producing this pigment.
In short, while PAR meters' estimations of PPFD are useful, it ignores the positive impacts of UV-A and far-red/infrared radiation.

Dana Riddle says it in clear scientific terms... I'm a hobbyist, my knowledge is what Dana would term anecdotal, but I concur. Excepting perhaps natural tropical sunlight, I've never seen anything that grows corals faster than Iwasaki 6500k bulbs. No, I don't use them anymore... got tired of dealing with the heat issues, but the most successful coral tank I ever owned was a 220g tank with 3x 400w Iwasaki 6500k bulbs above it, and a 5" Southdown DSB below it. I could grow _anything_ in that tank.

Dana Riddle says it in clear scientific terms... I'm a hobbyist, my knowledge is what Dana would term anecdotal, but I concur. Excepting perhaps natural tropical sunlight, I've never seen anything that grows corals faster than Iwasaki 6500k bulbs. No, I don't use them anymore... got tired of dealing with the heat issues, but the most successful coral tank I ever owned was a 220g tank with 3x 400w Iwasaki 6500k bulbs above it, and a 5" Southdown DSB below it. I could grow _anything_ in that tank.

Back in the dark ages (pun intended) we were pretty limited in lighting choices as far as metal halides went. The commercial coral farm I managed for a couple of years used only 6500K Iwasaki lamps and had great success. Many old timers to this day in the hobby still claim these lamps produced superior coral growth. I have some theories as to why and they are:
1. PAR meters don't measure the UV-A 365nm mercury spikes in these (or any) lamps. This energy is useful in photosynthesis. If we look at the pigments that protect against UV (the mycosporine-like amino acids, or MAAs) there are none that absorb UV energy at 365nm. There's a good reason for that.
2. The green light, what there is of it, borders on the absorption bandwidth of the accessory pigment peridinin. It's impact is positive, but probably minimal when compared to other bandwidths, but positive none the less.
3. The infrared energy relaxes pressure on Photosystem II by stimulating Photosystem I.
4. As far as coloration goes, we grew the Purple Monster Acropora successfully and it had magnificent color. Many of the other stony corals were quite colorful as well. Although not discussed much greenish-yellow/yellow light seems to induce non-fluorescent red coloration in those stony corals capable of producing this pigment.
In short, while PAR meters' estimations of PPFD are useful, it ignores the positive impacts of UV-A and far-red/infrared radiation.

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But dana, success now vs success in the dark ages, pretty different right? ; )

Also, isn't it true that only a 6500k halide would produce that uv-a, not an 6500k led or 6500k t5?

Coral+ and Blue+ is a nice balance for ambience (our eyes) and coral needs, but it wouldn't compete with the growth a 65k Iwasaki can produce.

This gets back to what jda was trying to explain to you.......... You're just misinterpreting, have it backwards slightly. There is more spectral waste today under setups than there ever was before under MH bulbs in general. It's part of what I was trying to explain to you in my thread. Excessive peaks regardless of which color can be detrimental because it creates a wacked out spectral distribution across the tank. Some corals may get what they want and some don't get what they need to thrive and color. You can do this with rainbow combos in T5s but you aren't generally going to trash corals.

As far as Echotech and BRS.............they're just trying to re-invent the wheel. The recommendations, how to set up.design ect. LEDs have been out there for 5+ years. People just weren't listening. It's always been more about spectrum than par.

Click to expand...

In the interest of not going back and forth with full page replys, I'm not going to address all of what you just said. It became too broad of a topic when you compared every light source today to metal halides ever. BOOM. head exploded. I was trying to focus purely on spectrum of the ati blue plus/coral + vs 6500k tropic t5 (or any other 6500k t5 bulb but I think that one is the best). Halide vs t5 vs led is a whole other topic.

I am technically working right now after all ; ) if we were talking in person I'd be happy to, but it would be way too annoying and time consuming for me to get after all that on my phone at work. My thumbs already hurt.

An interesting debate that reminds me of the old MH arguments and people tearing each other apart over 10k bulbs being too blue and actinic will kill all your corals.

These days we have so many options and there are documented success growing coral under just about everything. Pick a spectrum you like visually and be happy. We can easily add power if you want more PAR or PUR and there are so many things that impact growth more than spectrum (ok, I am talking about normal reefing bulbs - not something silly like 100% green LEDs) heck I have used 6.5k MH, 15kMH, all sorts of T5, PC, blue/white led, blue only LED, full spectrum LED, t5/LED combo - they all grew coral like weeds. If you are having trouble with coral growth it's not the spectrum, add or relocate a pump for flow, increase or decrease intensity, look at the tank chemistry more closely or best yet, spot feed appropriate sized food.

The spectrum seems to play such a minor role in coral growth (again, with normally used reef lights) compared to those other factors I listed that if you like 6.5k then run it! Like heavy blue? Run it! I think the valid point is that the more actinic the more fluorescence but you can wash out other colors with too much blues but whatever someone enjoys.

I do like the point that replicating nature isn't always the most ideal solution, there are so many variables in the ocean that we simply can't replicate in our living rooms and the example of tide pool coral growing slowly due to photoinhibition is a good one. Unless you like the look in which case there is 0 issues! We get caught up in "the best" argument a lot and it typically brings two things to mind.

1) there isn't anywhere nearly enough data out there to make that conclusion for each species and even individual morphs of a species
2) many times what people are arguing about isn't enough to make a significant impact anyway, it's just getting caught up in semantics

Click to expand...

This is 100% true lighting is a minimal factor compared to almost every other paramter.. I am amazed at how many articles I read claiming "this lighting solution is superior to all others BUYBUYBUY." Corals are highly sensitive to changes in lighting however with almost any stable lighting system you will be able to have a successful reef as the coral can adapt and utilize almost any spectrum. YES you can successfully grow any coral with just a regular T5 6700 bulb as long as the par is at least 100. The color will appear more brown/dull to your eyes but that does not mean the coral is not very healthy and happy. Visual color is only a matter of which wavelengths are reflected back to your eyes Its not even necessarily the spectrum that is being used by the coral lol.

I like 6500K because I can "see" the coral better. Some LFS wonder why I ask to turn off or down the blues, but I like less blue than most these days. To me Blue hides some of the fantastic differences with even the same piece of coral. Don't get me wrong, I run closer to 12 -14 K more of the time than not to get the florescent illumination of some coral, but others look better around 10K.

But dana, success now vs success in the dark ages, pretty different right? ; )

Also, isn't it true that only a 6500k halide would produce that uv-a, not an 6500k led or 6500k t5?

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Success growing Acropora corals or any other genera is success, regardless of the timeframe. The big difference now is the number of colorful corals available and advances in hardware, but that shouldn't diminish successes the Europeans had with stony corals in the 80's/90's or what many North Americans did as well when using the Iwasaki 6500 DL lamps. Any lamp containing mercury will produce line spectra of various wavelengths, including UV-A at 365nm, violet at 405 nm, and so on, although intensity will vary.